The present invention generally relates to fluid control systems which employ sensors for determining a state of fluids in the system and more particularly to such systems in which ease of maintenance is provided.
In some fluid control systems, a pump may be employed to pressurize fluid which is then driven through a closed-loop path to activity points of the system. For example, a hydraulic control system may use pressurized fluid to activate cylinders or hydraulic motors. Or, a cooling system may use pressurized cooling fluid to transfer heat to or from various sources of heat. During operation of such fluid control systems, it may be desirable to determine the pressure and/or temperature of the fluid at various locations within the system. Pressure sensors and/or temperature sensors may be employed to continuously measure these parameters.
Fluid control systems are often incorporated into vehicles such as aircraft. Aircraft fluid control systems may require routine maintenance to assure continued safe operability. The pressure and/or temperature sensors of these fluid control systems may need to be repaired or replaced during maintenance. Sensor replacement requires opening of the closed-loop fluid system and removal of the fluid from the system. Many fluid control systems contain a substantial quantity of expensive specialized fluid. Efforts associated with draining and re-filling the fluid control system and possible loss of the fluid contribute to high maintenance costs of vehicles such as aircraft.
In some aircraft, the sensors may be located in various positions in the aircraft which may not be readily accessible for routine maintenance. Gaining access to sensors for maintenance purposes may also contribute to high maintenance costs.
As can be seen, there is a need to provide fluid control systems in which replacing and/or repairing of sensors may be performed without a need to drain and refill, or de-pressurize the fluid control system. Furthermore there is a need to provide such fluid control system wherein the sensors may be readily accessible for maintenance purposes.